Electrolyte solution for non-aqueous electrolyte battery, and non-aqueous electrolyte battery using the same

ABSTRACT

The present invention provides an electrolyte solution for a non-aqueous electrolyte battery capable of an exerting high average discharge voltage and an excellent low-temperature output characteristic at −30° C. or lower and an excellent cycle characteristic and an excellent storage characteristic at high temperatures of 50° C. or higher, as well as a non-aqueous electrolyte battery containing the same. The present electrolyte solution comprises anon-aqueous solvent, a solute, at least one silane compound represented by the following general formula (1) as a first compound, and a fluorine-containing compound represented by the following general formula (3), for example, as a second compound.

TECHNICAL FIELD

The present invention relates to an electrolyte solution for anon-aqueous electrolyte battery comprising a specific silane compoundand a salt having a fluorophosphoryl structure and/or a fluorosulfonylstructure, as well as a non-aqueous electrolyte battery containing theelectrolyte solution.

BACKGROUND ART

In recent years, power storage systems to be applied for smallapparatuses that need high energy density, such as informationtechnology-related apparatuses or communication apparatuses,specifically, personal computers, video cameras, digital still cameras,and cell phones, and power storage systems to be applied for largeapparatuses that need power, such as electric vehicles, hybrid vehicles,auxiliary power for fuel cell vehicles, and energy storage have receivedattention. As a candidate therefor, non-aqueous electrolyte batteriessuch as a lithium ion battery, a lithium battery, a lithium ioncapacitor, or a sodium ion battery, have been actively developed.

Many of these non-aqueous electrolyte batteries have already been putinto practical use, but none of these batteries has satisfactoryproperties for use in various applications. In particular, a non-aqueouselectrolyte battery to be mounted on a vehicle such as an electricvehicle is required to have a high input output characteristic even in acold season. Hence, improvement in a low-temperature characteristic isimportant. In addition to the low-temperature characteristic, such abattery is required to have a high-temperature cycle characteristic suchthat reduction in capacity is small even when charging and dischargingare performed repeatedly under a high temperature environment (ahigh-temperature cycle characteristic) and self-discharging is smalleven when the battery is placed in a fully charged state for a longperiod of time under a high temperature environment (a high-temperaturestorage characteristic).

As a means for improving the high-temperature characteristic, and thebattery characteristic (a cycle characteristic) wherein charging anddischarging are repeated, optimization of various battery componentsincluding active materials of positive electrodes and negativeelectrodes has been studied. A non-aqueous electrolyte solution-relatedtechnology is not an exception, and it has been proposed thatdeterioration due to decomposition of an electrolyte solution on thesurface of an active positive electrode or an active negative electrodeis suppressed by various additives. For example, Patent Document 1proposes that battery characteristics are improved by the addition of avinylene carbonate to an electrolyte solution. However, there was aproblem in that battery characteristics at high temperatures areimproved, but the internal resistance is significantly increased tolower the low-temperature characteristic. Addition of a silicon compoundto an electrolyte solution has been also studied. Alternatively,examination has been made on addition of a silicon compound to anelectrolyte solution, for example, as shown in Patent Documents 2 to 6,which propose addition of a silicon compound such as a silicone compoundor a fluorosilane compound, to a non-aqueous electrolyte solution forthe purpose of improving a cycle characteristic of the non-aqueouselectrolyte battery and for inhibiting internal resistance elevation soas to improve a high-temperature storage characteristic and alow-temperature characteristic of the non-aqueous electrolyte battery.In addition, Patent Document 7 proposes addition of a fluorosilanecompound or a difluorophosphoric acid compound in order to improve alow-temperature characteristic of the non-aqueous electrolyte battery.Furthermore, examination has been conducted on the addition of a saltcontaining a phosphoryl group or a sulfonyl group to an electrolytesolution. For example, there have been proposed a method (PatentDocument 8) for improving a high-temperature cycle characteristic or ahigh-temperature storage characteristic by combining a specificsulfonimide salt or phosphoryl imide salt with an oxalato complex; and amethod (Patent Document 9) for improving a cycle characteristic or anoutput characteristic by combining a specific fluorophosphate with asulfonimide salt.

PRIOR ART DOCUMENTS Patent Documents

-   Patent Document 1: JP Patent Publication (Kokai) No. 2000-123867 A-   Patent Document 2: JP Patent Publication (Kokai) No. 8-078053 A-   Patent Document 3: JP Patent Early-Publication (Kokai) No.    2002-033127 A-   Patent Document 4: JP Patent Early-Publication (Kokai) No.    2004-039510 A-   Patent Document 5: JP Patent Early-Publication (Kokai) No.    2004-087459 A-   Patent Document 6: JP Patent Early-Publication (Kokai) No.    2008-181831 A-   Patent Document 7: JP Patent Early-Publication (Kokai) No.    2007-149656 A-   Patent Document 8: JP Patent Early-Publication (Kokai) No.    2013-051122 A-   Patent Document 9: JP Patent Early-Publication (Kokai) No.    2013-030465 A-   Patent Document 10: JP Patent Early-Publication (Kokai) No.    10-139784 A-   Patent Document 11: JP Patent Early-Publication (Kokai) No.    2008-222484 A

Non-Patent Documents

-   Non-patent Document 1: Tetrahedron, 42(11), 2821-2829 (1986)-   Non-patent Document 2: Journal of the American Chemical Society, 72,    4956-4958, (1950)-   Non-patent Document 3: Faraday Discussion, 145, 281-299, (2010)

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

There is still a room for the batteries disclosed in the Prior ArtDocuments in order to improve the low-temperature output characteristic,high-temperature cycle characteristic, and high-temperature storagecharacteristic. In particular, there is a problem for the batteries thatat a low temperature, since the internal resistance of the batteries isincreased, discharge voltage is largely decreased and accordingly it isnot possible to obtain sufficient discharge voltage. Further, there is aproblem in that, when a silane compound having an Si—F bond or an Si—Obond is used, the internal resistance of the batteries is extremely highand accordingly the output characteristic is greatly reduced. Thepresent invention provides an electrolyte solution for a non-aqueouselectrolyte battery capable of exerting a high average discharge voltageand an excellent low-temperature output characteristic at −30° C. orlower and an excellent cycle characteristic and an excellent storagecharacteristic at high temperatures of 50° C. or higher, as well as anon-aqueous electrolyte battery containing the same.

Means for Solving the Problems

The present inventors have made intensive studies in order to resolvethe above mentioned problems, and as a result, have discovered that anon-aqueous electrolyte battery can exert an excellent low-temperaturecharacteristic, a high-temperature cycle characteristic, and ahigh-temperature storage characteristic, when a non-aqueous electrolytesolution for a non-aqueous electrolyte battery containing a non-aqueoussolvent and a solute contains (1) a specific silane compound and (2) atleast one compound selected from the group consisting of afluorine-containing compound having a specific structure (afluorophosphate having a specific structure, an imide salt having aspecific fluorophosphoryl structure and/or a specific fluorosulfonylstructure). The present invention has been completed based on thisfinding.

Specifically, the present invention provides an electrolyte solution fora non-aqueous electrolyte battery (which may be sometimes hereinafteralso referred to simply as “non-aqueous electrolyte solution” or“electrolyte solution”), including at least a non-aqueous solvent, asolute, at least one silane compound represented by the followinggeneral formula (1) as a first compound, and at least one compoundselected from the group consisting of fluorine-containing compoundsrepresented by the following general formulae (2) to (9) as a secondcompound.

In general formula (1),

R¹ each independently represents a group having a carbon-carbonunsaturated bond,

R² each independently represents a linear or branched C₁₋₁₀ alkyl group,which may optionally contain a fluorine atom and/or an oxygen atom, and

a is 2 to 4.

In general formulae (2) to (4) and (6) to (8),

R³ to R⁶ each independently represent a fluorine atom or an organicgroup selected from a linear or branched C₁₋₁₀ alkoxy group, a C₂₋₁₀alkenyloxy group, a C₂₋₁₀ alkynyloxy group, a C₃₋₁₀ cycloalkoxy group, aC₃₋₁₀ cycloalkenyloxy group, and a C₆₋₁₀ aryloxy group, wherein afluorine atom, an oxygen atom, or an unsaturated bond may optionally bepresent in the organic group as well.

In general formulae (4), (5), (8), and (9),

X¹ and X² each independently represent a fluorine atom or an organicgroup selected from a linear or branched C₁₋₁₀ alkyl group, a C₂₋₁₀alkenyl group, a C₂₋₁₀ alkynyl group, a C₃₋₁₀ cycloalkyl group, a C₃₋₁₀cycloalkenyl group, a C₆₋₁₀ aryl group, a linear or branched C₁₋₁₀alkoxy group, a C₂₋₁₀ alkenyloxy group, a C₂₋₁₀ alkynyloxy group, aC₃₋₁₀ cycloalkoxy group, a C₃₋₁₀ cycloalkenyloxy group, and a C₆₋₁₀aryloxy group, wherein a fluorine atom, an oxygen atom, or anunsaturated bond may optionally be present in the organic group as well.

The general formulae (2) to (9) have at least one P—F bond and/or atleast one S—F bond.

M¹ and M² each independently represent a proton, a metal cation or anonium cation.

It is important that the electrolyte solution for a non-aqueouselectrolyte battery of the present invention comprises the firstcompound and the second compound in combination. The reason is that,only when including these two compounds in combination, the electrolytesolution used in a non-aqueous electrolyte battery can exert a highaverage discharge voltage and excellent low-temperature outputcharacteristics at −30° C. or lower and an excellent cyclecharacteristics and excellent storage characteristics at hightemperatures of 50° C. or higher.

The amount of the first compound to be added preferably ranges from0.001 to 10.0% by mass relative to the total amount of the electrolytesolution for a non-aqueous electrolyte battery.

The amount of the second compound to be added preferably ranges from0.001 to 10.0% by mass relative to the total amount of the electrolytesolution for a non-aqueous electrolyte battery.

The group represented by R¹ in the general formula (1) preferably eachindependently represents a group selected from the group consisting of avinyl group, an allyl group, a 1-propenyl group, a 2-propenyl group, anethynyl group, and a 2-propynyl group.

The group represented by R² in the general formula (1) preferably eachindependently represents a group selected from the group consisting of amethyl group, an ethyl group, a propyl group, a 2,2,2-trifluoroethylgroup, a 2,2,3,3-tetrafluoropropyl group, a 1,1,1-trifluoroisopropylgroup, and a 1,1,1,3,3,3-hexafluoroisopropyl group.

R³ to R⁶ in the general formulae (2) to (4) and (6) to (8) preferablyrepresent a fluorine atom or an organic group selected from the groupconsisting of a fluorine-containing linear or branched C₁₋₁₀ alkoxygroup, a C₂₋₁₀ alkenyloxy group, and a C₂₋₁₀ alkynyloxy group.

It is more preferable that the alkoxy group is selected from the groupconsisting of a 2,2,2-trifluoroethoxy group, a2,2,3,3-tetrafluoropropoxy group, a 1,1,1-trifluoroisopropoxy group, anda 1,1,1,3,3,3-hexafluoroisopropoxy group, the alkenyloxy group isselected from the group consisting of a 1-propenyloxy group, a2-propenyloxy group, and a 3-butenyloxy group, and the alkynyloxy groupis selected from the group consisting of a 2-propynyloxy group and a1,1-dimethyl-2-propynyloxy group.

X¹ and X² in the general formulae (4), (5), (8), and (9) is preferably afluorine atom or an organic group selected from the group consisting ofa linear or branched C₁₋₁₀ alkoxy group, a C₂₋₁₀ alkenyloxy group and aC₂₋₁₀ alkynyloxy group.

It is preferable that the alkoxy group is selected from the groupconsisting of a methoxy group, an ethoxy group, and a propoxy group, thealkenyloxy group is selected from the group consisting of a1-propenyloxy group, a 2-propenyloxy group, and a 3-butenyloxy group,and the alkynyloxy group is selected from the group consisting of a2-propynyloxy group and a 1,1-dimethyl-2-propynyloxy group.

M¹ and M² in the general formulae (2) to (9) preferably represent atleast one cation selected from the group consisting of a lithium ion, asodium ion, a potassium ion, a tetraalkylammonium ion, and atetraalkylphosphonium ion.

The solute is preferably at least one solute selected from the groupconsisting of lithium hexafluorophosphate (LiPF₆), lithiumtetrafluoroborate (LiBF₄), lithium bis(trifluoromethanesulfonyl)imide(LiN(CF₃SO₂)₂), lithium bis(fluorosulfonyl)imide (LiN(FSO₂)₂), lithiumbis(difluorophosphoryl)imide (LiN(POF₂)₂), sodium hexafluorophosphate(NaPF₆), sodium tetrafluoroborate (NaBF₄), sodiumbis(trifluoromethanesulfonyl)imide (NaN(CF₃SO₂)₂), sodiumbis(fluorosulfonyl)imide (NaN(FSO₂)₂), and sodiumbis(difluorophosphoryl)imide (NaN(POF₂)₂).

The non-aqueous solvent is preferably at least one non-aqueous solventselected from the group consisting of a cyclic carbonate, a linearcarbonate, a cyclic ester, a linear ester, a cyclic ether, a linearether, a sulfone compound, a sulfoxide compound, and an ionic liquid.

The present invention provides a non-aqueous electrolyte battery (whichmay be sometimes hereinafter also referred to simply as “non-aqueousbattery” or “battery”), comprising at least a positive electrode, anegative electrode, a separator, and the electrolyte solution for anon-aqueous electrolyte battery as stated above.

Effects of the Invention

The present invention can provide an electrolyte solution for anon-aqueous electrolyte battery capable of exerting a high averagedischarge voltage and excellent low-temperature output characteristicsat −30° C. or lower and an excellent cycle characteristics and excellentstorage characteristics at high temperatures of 50° C. or higher whenused for a non-aqueous electrolyte battery, as well as a non-aqueouselectrolyte battery containing the same.

MODES FOR CARRYING OUT THE INVENTION

The present invention will be described in detail. However, theexplanations for the constituent features described below are merelyexamples of the embodiments of the present invention, and the scope ofthe present invention is not limited to these specific embodiments. Thepresent invention may be variously modified and implemented within thewhole disclosure of the present application.

The electrolyte solution for a non-aqueous electrolyte battery of thepresent invention is an electrolyte solution for a non-aqueouselectrolyte battery, comprising at least a non-aqueous solvent, asolute, at least one silane compound represented by the above generalformula (1) as a first compound, and at least one compound selected fromthe group consisting of fluorine-containing compounds represented by theabove general formulae (2) to (9) as a second compound.

The first compound decomposes on a positive electrode and/or a negativeelectrode so as to form a stable film, which suppresses deterioration ofthe battery. In the case wherein the first compound is not used incombination with the second compound but the first compound is onlyused, there would be generated a problem in that the film formed on theelectrode serves as a great resistance to the movement of lithium ionsduring charge and discharge, whereby the resultant non-aqueouselectrolyte battery has markedly decreased low-temperaturecharacteristics. In addition, the high-temperature cycle characteristicand a high-temperature storage characteristic at high temperatures of50° C. or higher are insufficient.

Similarly, the second compound partially decomposes on a positiveelectrode and/or a negative electrode, so as to form a highlyionically-conductive film on the surfaces of the positive electrode andthe negative electrode. This film prevents the non-aqueous solvent andthe solute from directly contacting an electrode active material,thereby preventing decomposition of the non-aqueous solvent and thesolute, suppressing deterioration of battery performance. In the casewherein the second compound is not used together with the first compoundand the second compound is singly used, the number of the film formingcomponents is small, whereby the resultant non-aqueous electrolytebattery has an insufficient high-temperature cycle characteristic and aninsufficient high-temperature storage characteristic at hightemperatures of 50° C. or higher as well as an insufficientlow-temperature characteristic.

By using the first compound and the second compound together in theelectrolyte solution for a non-aqueous electrolyte battery of thepresent invention, when compared to the case wherein the first compoundis singly used, the high-temperature cycle characteristic andhigh-temperature storage characteristic at high temperatures of 50° C.or higher as well as a low-temperature characteristic are improved,whereby the object of the present invention is successfully achieved.The detailed mechanism of this phenomenon is not clear, but it isassumed as follows: when the first and second compounds are presenttogether, both of the first compound and the second compound activelydecompose on the positive electrode and negative electrode, so that theresultant film has a higher ionic conductance and durability than thesingle use of either of the first and second compounds. It is consideredthat this indicates that the decomposition of the solvent and the soluteat high temperatures is suppressed and resistance elevation at lowtemperatures is also suppressed. In particular, it is assumed that amore amount of fluorophosphoryl structure and/or fluorosulfonylstructure is contained in the resultant film and accordingly, there iscaused a deviation in charge distribution within the film, which impartsthe film with a high lithium conductivity, i.e. the film having a lowresistance (this means that the film has a good output characteristic).It is also assumed that the more the amount of unsaturated bondcontaining moieties is contained in the first compound and the secondcompound, the more likely the first compound and the second compound areto decompose on the positive electrode and the negative electrode, thehigher the durability of the resultant film is, and the more excellentthe effects described above are. It is also assumed that when a moietyhaving a higher electron withdrawing (fluorine atoms and fluorinecontaining alkoxy groups, for example) is contained in the secondcompound, the deviation in charge distribution becomes larger, whereby alower resistant film (the film having a better output characteristic) isformed.

For the reasons as stated above, it is assumed that the use of the firstcompound and the second compound together improves an average dischargevoltage (output characteristic) at temperatures of −30° C. or lower anda cycle characteristic and a storage characteristic at high temperaturesof 50° C. or higher, as compared with the single use of either of thefirst and second compounds.

The electrolyte solution for a non-aqueous electrolyte battery of thepresent invention comprises the first compound, the second compound, anon-aqueous organic solvent, and the solute. If necessary, theelectrolyte solution for a non-aqueous electrolyte battery of thepresent invention may also comprise another additive which is generallyknown in the art. In the following, the constituent elements of theelectrolyte solution for a non-aqueous electrolyte battery of thepresent invention will be described in detail.

First Compound

Examples of the group represented as R¹ in the above general formula (1)having a carbon-carbon unsaturated bond include C₂₋₈ alkenyl groups suchas a vinyl group, an allyl group, a 1-propenyl group, a 2-propenylgroup, an isopropenyl group, a 2-butenyl group, and a 1,3-butadienylgroup, alkenyloxy groups derived from these C₂₋₈ alkenyl groups, C₂₋₈alkynyl groups such as an ethynyl group, a 2-propynyl group, and a1,1-dimethyl-2-propynyl group, alkynyloxy groups derived from these C₂₋₈alkynyl groups, C₆₋₁₂ aryl groups such as a phenyl group, a tolyl group,and a xylyl group, and aryloxy groups derived from these C₆₋₁₂ arylgroups. The group represented as R¹ may contain a fluorine atom and/oran oxygen atom. Among them, those groups which contain 6 or less carbonsand have a carbon-carbon unsaturated bond are preferable. In the casewherein the number of the carbons is greater than 6, the resistanceafter a film is formed on the electrode tends to be relatively high.More specifically, the group selected from the group consisting of avinyl group, an allyl group, a 1-propenyl group, a 2-propenyl group, anethynyl group and a 2-propynyl group is preferable.

The number “a” of groups having a carbon-carbon unsaturated bond isrequired to be from 2 to 4 in order to form a film on an electrode,eventually in order to attain the object of the present invention, andis preferably from 3 to 4 in order to form a strong film.

Examples of the alkyl group represented as R² in the above generalformula (1) include C₁₋₁₂ alkyl groups such as a methyl group, an ethylgroup, a propyl group, an isopropyl group, an n-butyl group, a sec-butylgroup, an isobutyl group, a tert-butyl group and a pentyl group. Thealkyl group represented as R² may contain a fluorine atom and/or anoxygen atom (in the case wherein an oxygen atom is contained, the alkylgroup represented as R² means a structure other than an alkoxy group;more specifically, the oxygen atom is not bonded to the silicon atom ingeneral formula (1)). Among these groups, those groups selected from thegroup consisting of a methyl group, an ethyl group, a propyl group, a2,2,2-trifluoroethyl group, a 2,2,3,3-tetrafluoropropyl group, a1,1,1-trifluoroisopropyl group, and a 1,1,1,3,3,3-hexafluoroisopropylgroup are particularly preferable, in order to provide a non-aqueouselectrolyte battery having a more improved high-temperature cyclecharacteristic and high-temperature storage characteristic, withoutincreasing the internal resistance of the battery.

The lower limit of the amount of the first compound to be added ispreferably 0.001% by mass or more, more preferably 0.01% by mass ormore, further more preferably 0.1% by mass or more, and the upper limitof the amount of the first compound to be added is preferably 10.0% bymass or less, more preferably 5.0% by mass or less, further morepreferably 2.0% by mass or less relative to the total amount of theelectrolyte solution for a non-aqueous electrolyte battery. The amountof the first compound to be added that is lower than 0.001% by mass maymake it difficult to obtain an effect of sufficiently improving ahigh-temperature storage characteristic of the resultant non-aqueouselectrolyte battery. On the other hand, the amount of the first compoundto be added of higher than 10.0% by mass may greatly increase theinternal resistance of the battery, which would cause a problem in thatthe low-temperature output characteristic is impaired. One kind of thefirst compound may be singly used, or a plurality of kinds thereof maybe used. The term “the total amount of the electrolyte solution for anon-aqueous electrolyte battery” refers to the sum of the amounts of allthe non-aqueous solvent, the solute, the first compound and the secondcompound.

Specific examples of the silane compound represented by the abovegeneral formula (1) include the following compounds No. 1 to No. 13.However, the silane compound used in the present invention is notlimited to these compounds.

The silane compound represented by the above general formula (1) may beproduced, as described in Patent Document 10 and Non-patent Document 1,for example, by reacting a silicon compound containing a silanol groupor a hydrolyzable group with an organic metal reagent having acarbon-carbon unsaturated bond, so as to replace the silanol group orthe hydrolyzable group in the silicon compound by the group having acarbon-carbon unsaturated bond, thus producing the present siliconcompound having a carbon-carbon unsaturated bond.

Second Compound

It is important for achieving the object of the present invention thatthe above general formulae (2) to (9) have at least one of a P—F bondand/or S—F bond. When no P—F bond or S—F bond is contained, alow-temperature characteristic cannot be improved. The more the numberof P—F bonds and S—F bonds is, the more excellent low-temperaturecharacteristic is obtained, and is preferable.

Examples of the cation represented as M¹ and M² in the above generalformulae (2) to (9) include a proton, a metal cation, and an oniumcation. Any type of the cations may be used with no restrictions, solong as they do not deteriorate the performance of the electrolytesolution for a non-aqueous electrolyte battery of the present inventionand the non-aqueous electrolyte battery, and any cations may be selectedfrom among the cations as stated above without any restrictions.Specific examples thereof include cations of metals such as lithium,sodium, potassium, rubidium, cesium, magnesium, calcium, barium, silver,copper and iron, and cations of oniums such as tetraalkylammonium,tetraalkylphosphonium and imidazolium derivatives. From the viewpoint ofimproving ionic conductance within the non-aqueous electrolyte battery,a lithium ion, a sodium ion, a potassium ion, a tetramethylammonium ion,a tetraethylammonium ion, a tetrabutylphosphonium ion, and the like areparticularly preferable.

In the above general formulae (2) to (4) and (6) to (8), the alkoxygroup represented by R³ to R⁶ includes C₁₋₁₀ alkoxy groups andfluorine-containing alkoxy groups, such as a methoxy group, an ethoxygroup, a propoxy group, an isopropoxy group, a butoxy group, a secondarybutoxy group, a tertiary butoxy group, a pentyloxy group, atrifluoromethoxy group, a 2,2-difluoroethoxy group, a2,2,2-trifluoroethoxy group, a 2,2,3,3-tetrafluoropropoxy group, a1,1,1-trifluoroisopropoxy group, and a 1,1,1,3,3,3-hexafluoroisopropoxygroup; the alkenyloxy group represented by R³ to R⁶ includes C₂₋₁₀alkenyloxy groups and fluorine-containing alkenyloxy groups, such as avinyloxy group, a 1-propenyloxy group, a 2-propenyloxy group, anisopropenyloxy group, a 2-butenyloxy group, a 3-butenyloxy group and a1,3-butadienyloxy group; the alkynyloxy group represented by R³ to R⁶includes C₂₋₁₀ alkynyloxy groups and fluorine-containing alkynyloxygroups, such as an ethynyloxy group, a 2-propynyloxy group and a1,1-dimethyl-2-propynyloxy group; the cycloalkoxy group represented byR³ to R⁶ includes C₃₋₁₀ cycloalkoxy groups and fluorine-containingcycloalkoxy groups, such as a cyclopentyloxy group and a cyclohexyloxygroup; the cycloalkenyloxy group represented by R³ to R⁶ includes C₃₋₁₀cycloalkenyloxy groups and fluorine-containing cycloalkenyloxy groups,such as a cyclopentenyloxy group and a cyclohexenyloxy group; and thearyloxy group represented by R³ to R⁶ includes C₆₋₁₀ aryloxy groups andfluorine-containing aryloxy groups, such as a phenyloxy group, atolyloxy group and a xylyloxy group.

R³ to R⁶ in the above general formulae (2) to (4) and (6) to (8) arepreferably fluorine atoms or alkoxy groups containing a fluorine atom,because the strong electron-withdrawing property thereof improves iondissociation degree, thereby increasing ionic conductance in a solutionand a composition. Further, R³ to R⁶ in the above general formulae (2)to (4) and (6) to (8) are more preferably fluorine atoms, because thesmaller anion size improves mobility, so as to significantly increasethe degree of ionic conductance in a solution or a composition. For thisreason, it is assumed that the greater the number of P—F bonds in theabove general formulae (2) to (9) is, the greater the low-temperaturecharacteristic is improved. Furthermore, the above R³ to R⁶ arepreferably organic groups selected from the group consisting of analkenyloxy group and an alkynyloxy group. Unlike the above alkenyloxygroup and alkynyloxy group, a hydrocarbon group with no interveningoxygen atom is not preferred because of its weak electron-withdrawingproperty which causes a decrease in ion dissociation degree and adecrease in ionic conductance in a solution or a composition. As in thecase of the alkenyloxy group and the alkynyloxy group, a group having anunsaturated bond is preferable because decomposition on the positiveelectrode and the negative electrode proceeds actively and the resultantfilm is higher in durability. Furthermore, the high number of carbonstends to result in an increased anion size and decreased ionicconductance in a solution or a composition, and accordingly, the numberof carbons of the above R³ to R⁶ is preferably 6 or less. When thenumber of carbons is 6 or less, the resultant ionic conductance tends tobe relatively high and accordingly is preferable. The organic group isparticularly preferably a group selected from the group consisting of a1-propenyloxy group, a 2-propenyloxy group, a 3-butenyloxy group, a2-propynyloxy group and a 1,1-dimethyl-2-propynyloxy group, because oftheir relatively small anion sizes.

In the above general formulae (4), (5), (8), and (9), the alkyl grouprepresented by X¹ and X² includes C₁₋₁₀ alkyl groups andfluorine-containing alkyl groups, such as a methyl group, an ethylgroup, a propyl group, an isopropyl group, a butyl group, a secondarybutyl group, a tertiary butyl group, a pentyl group, a trifluoromethylgroup, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a2,2,3,3-tetrafluoropropyl group and a 1,1,1,3,3,3-hexafluoroisopropylgroup; the alkenyl group represented by X¹ and X² includes C₂₋₁₀ alkenylgroups and fluorine-containing alkenyl groups, such as a vinyl group, a1-propenyl group, a 2-propenyl group, an isopropenyl group, a 2-butenylgroup, a 3-butenyl group and a 1,3-butadienyl group; the alkynyl grouprepresented by X¹ and X² includes C₂₋₁₀ alkynyl groups andfluorine-containing alkynyl groups, such as an ethynyl group, a2-propynyl group and a 1,1-dimethyl-2-propynyl group; the cycloalkylgroup represented by X¹ and X² includes C₃₋₁₀ cycloalkyl groups andfluorine-containing cycloalkyl groups, such as a cyclopentyl group and acyclohexyl group; the cycloalkenyl group represented by X¹ and X²includes C₃₋₁₀ cycloalkenyl groups and fluorine-containing cycloalkenylgroups, such as a cyclopentenyl group and a cyclohexenyl group; the arylgroup represented by X¹ and X includes C₆₋₁₀ aryl groups andfluorine-containing aryl groups, such as a phenyl group, a tolyl groupand a xylyl group; the alkoxy group represented by X¹ and X² includesC₁₋₁₀ alkoxy groups and fluorine-containing alkoxy groups, such as amethoxy group, an ethoxy group, a propoxy group, an isopropoxy group, abutoxy group, a secondary butoxy group, a tertiary butoxy group, apentyloxy group, a trifluoromethoxy group, a 2,2-difluoroethoxy group, a2,2,2-trifluoroethoxy group, a 2,2,3,3-tetrafluoropropoxy group and a1,1,1,3,3,3-hexafluoroisopropoxy group; the alkenyloxy group representedby X¹ and X² includes C₂₋₁₀ alkenyloxy groups and fluorine-containingalkenyloxy groups, such as a vinyloxy group, a 1-propenyloxy group, a2-propenyloxy group, an isopropenyloxy group, a 2-butenyloxy group, a3-butenyloxy group and a 1,3-butadienyloxy group; the alkynyloxy grouprepresented by X¹ and X² includes C₂₋₁₀ alkynyloxy groups andfluorine-containing alkynyloxy groups, such as an ethynyloxy group, a2-propynyloxy group and a 1,1-dimethyl-2-propynyloxy group; thecycloalkoxy group represented by X¹ and X² includes C₃₋₁₀ cycloalkoxygroups and fluorine-containing cycloalkoxy groups, such as acyclopentyloxy group and a cyclohexyloxy group; the cycloalkenyloxygroup represented by X¹ and X² includes C₃₋₁₀ cycloalkenyloxy groups andfluorine-containing cycloalkenyloxy groups, such as a cyclo pentenyloxygroup and a cyclohexenyloxy group; and the aryloxy group represented byX¹ and X² includes C₆₋₁₀ aryloxy groups and fluorine-containing aryloxygroups, such as a phenyloxy group, a tolyloxy group and a xylyloxygroup.

X¹ and X² in the above general formulae (4), (5), (8), and (9) arepreferably fluorine atoms, because the strong electron-withdrawingproperty of fluorine atom improves ion dissociation degree and its loweranion size improves mobility, so as to significantly increase the degreeof ionic conductance in a solution or a composition. Furthermore, theabove X¹ and X² are preferably organic groups selected from the groupconsisting of an alkoxy group, an alkenyloxy group and an alkynyloxygroup. Unlike the above alkoxy group, alkenyloxy group, and alkynyloxygroup, a hydrocarbon group with no intervening oxygen atom is notpreferred because of its weak electron-withdrawing property, whichcauses a decrease in ion dissociation degree and a decrease in ionicconductance in a solution or a composition. Furthermore, the highernumber of carbons tends to result in an increased anion size anddecreased ionic conductance in a solution or a composition. Hence, thenumber of carbons of the above X is preferably 6 or less. It ispreferable that when the number of carbons is 6 or less, the resultantionic conductance tends to be relatively high. The organic group isparticularly preferably when it is selected from the group consisting ofa methoxy group, an ethoxy group, a propoxy group, a 1-propenyloxygroup, a 2-propenyloxy group, a 3-butenyloxy group, a 2-propynyloxygroup and a 1,1-dimethyl-2-propynyloxy group, because of theirrelatively small anion sizes.

In the case wherein the compound has the structure as represented by anyof the above general formula (2), (6), (7) and (8) wherein all of R³ toR⁵ and X¹ are hydrocarbon groups with an intervening oxygen atom (analkoxy group, an alkenyloxy group, an alkynyloxy group, a cycloalkoxygroup, a cycloalkenyloxy group and an aryloxy group), more specificallythe compound containing no a P—F bond or an S—F bond, the solubility ofthe compound in the non-aqueous electrolyte solution is very low (lowerthan 0.001% by mass, for example) and therefore it is difficult toachieve the object of the present invention even when such a compound isadded to the non-aqueous electrolyte solution.

The lower limit of the amount of the second compound to be added ispreferably 0.001% by mass or more, more preferably 0.01% by mass ormore, further more preferably 0.1% by mass or more, and the upper limitof the amount of the second compound to be added is preferably 10.0% bymass or less, more preferably 5.0% by mass or less, further morepreferably 2.0% by mass or less, relative to the total amount of theelectrolyte solution for a non-aqueous electrolyte battery. When theamount of the second compound to be added is lower than 0.001% by mass,it may be difficult to sufficiently improve an output characteristic ofthe resultant non-aqueous electrolyte battery at low temperatures. Onthe other hand, when the amount of the second compound to be added ishigher than 10.0% by mass, the improving effect cannot be obtained evenby the addition of more than 10.0% by mass, and such addition is notonly useless, but also tends to increase the viscosity of theelectrolyte solution and decrease the ionic conductance, which easilyincreases the resistance and deteriorates the battery performance, andthus is not preferred. One type of the second compound may be addedalone, or plural types of the second compounds may be added incombination.

Specific examples of the phosphate anion represented by the abovegeneral formula (2) include the following compound No. 14. However, thephosphate used in the present invention is not limited to such acompound.

Specific examples of the imide salt anion represented by the abovegeneral formulae (3) to (9) include the following compounds No. 15 toNo. 50. However, the imide salt used in the present invention is notlimited to these compounds.

A salt having the phosphate anion represented by the above generalformula (2) may be produced, as described in Patent Document 11,Non-patent Document 2, and Non-patent Document 3, for example, byreacting a halide other than a fluoride, with LiPF₆ and water in anon-aqueous solvent, or by reacting a pyrophosphoric acid estercontaining an corresponding alkoxy group with hydrogen fluoride.

A salt having the imide anion represented by the above general formula(3) may be produced by any of various methods with no limitation. Forexample, the salt may be produced by reacting a corresponding phosphorylchloride (P(═O)R³R⁴Cl) with a phosphoramide (H₂NP(═O) R⁵R⁶) in thepresence of an organic base or an inorganic base.

A salt having the imide anion represented by the above general formula(4) may be produced by any of various methods with no limitation. Forexample, the salt may be produced by reacting a corresponding phosphorylchloride (P(═O)R³R⁴Cl) with a sulfonamide (H₂NSO₂X¹) in the presence ofan organic base or an inorganic base.

A salt having the imide anion represented by the above general formula(5) may be produced by any of various methods with no limitation. Forexample, the salt may be produced by reacting a corresponding sulfonylchloride (X¹SO₂Cl) with a corresponding sulfonamide (H₂NSO₂X²) in thepresence of an organic base or an inorganic base.

A salt having the imide anion represented by the above general formula(6) may be produced by any of various methods with no limitation. Forexample, the salt may be produced by reacting a corresponding phosphorylchloride (P(═O)R³R⁴Cl) with a corresponding phosphoramide (H₂NP(═O)R⁵O⁻)in the presence of an organic base or an inorganic base.

A salt having the imide anion represented by the above general formula(7) may be produced by any of various methods with no limitation. Forexample, the salt may be produced by reacting a corresponding phosphorylchloride (P(═O)R³R⁴Cl) with sulfamic acid (H₂NSO₃ ⁻) in the presence ofan organic base or an inorganic base.

A salt having the imide anion represented by the above general formula(8) may be produced by any of various methods with no limitation. Forexample, the salt may be produced by reacting a corresponding sulfonylchloride (X¹SO₂Cl) with a corresponding phosphoramide (H₂NP(═O)R³O⁻) inthe presence of an organic base or an inorganic base.

A salt having the imide anion represented by the above general formula(9) may be produced by any of various methods with no limitation. Forexample, the salt may be produced by reacting a corresponding sulfonylchloride (X¹SO₂Cl) with a corresponding sulfamic acid (H₂NSO₃ ⁻) in thepresence of an organic base or an inorganic base.

In these methods of producing the salts represented by general formulae(2) to (9) as stated above, cation exchange may be performed ifappropriate.

Non-Aqueous Solvent

Kinds of non-aqueous solvent to be used for the electrolyte solution fora non-aqueous electrolyte battery of the present invention are notparticularly limited, and any kinds of non-aqueous solvents can be used.Specific examples thereof include cyclic carbonates such as propylenecarbonate, ethylene carbonate, butylene carbonate and fluoroethylenecarbonate; linear carbonates such as diethyl carbonate, dimethylcarbonate and ethyl methyl carbonate; cyclic esters such asγ-butyrolactone and γ-valerolactone; linear esters such as methylacetate and methyl propionate; cyclic ethers such as tetrahydrofuran,2-methyltetrahydrofuran and dioxane; linear ethers such asdimethoxyethane and diethylether; and sulfone compounds or sulfoxidecompounds such as dimethyl sulfoxide and sulfolane. An ionic liquid andthe like, whose category is different from that of the above non-aqueoussolvents may be also used. Furthermore, one type of non-aqueous solventmay be used in the present invention or two or more types thereof withdiffering mixing ratios and in any combination may be used depending onapplications. Of these examples, in view of electrochemical stabilityagainst its oxidation-reduction and chemical stability relating to heator reaction with the above solute, propylene carbonate, ethylenecarbonate, fluoroethylene carbonate, diethyl carbonate, dimethylcarbonate and ethyl methyl carbonate are particularly preferred.

Solute

Any kinds of the solutes may be used for the electrolyte solution for anon-aqueous electrolyte battery of the present invention and are notparticularly limited, and any kinds of electrolyte salts can be used.Specific examples thereof include: in the case of a lithium battery anda lithium ion battery, electrolyte salts represented by LiPF₆, LiBF₄,LiClO₄, LiAsF₆, LiSbF₆, LiCF₃SO₃, LiN(CF₃SO₂)₂, LiN(FSO₂)₂,LiN(C₂F₅SO₂)₂, LiN(CF₃SO₂) (C₄F₉SO₂), LiC(CF₃SO₂)₃, LiPF₃ (C₃F₇)₃,LiB(CF₃)₄, LiBF₃(C₂F₅), and LiN(POF₂)₂; and in the case of a sodium ionbattery, electrolyte salts represented by NaPF₆, NaBF₄, NaCF₃SO₃,NaN(CF₃SO₂)₂, NaN(FSO₂)₂, and NaN(POF₂)₂. One kind of the solute may beused independently, and two or more types thereof may be mixed at anyratio and in any combination, depending on applications. Of theseexamples, in view of energy density, output characteristic, life and thelike for a battery, LiPF₆, LiBF₄, LiN(CF₃SO₂)₂, LiN(FSO₂)₂,LiN(C₂F₅SO₂)₂, LiN(POF₂)₂, NaPF₆, NaBF₄, NaN(CF₃SO₂)₂, NaN(FSO₂)₂, andNaN(POF₂)₂ are preferred.

The concentration of the solute is not particularly limited. The lowerlimit of the concentration is preferably 0.5 mol/L or more, morepreferably 0.7 mol/L or more, further more preferably 0.9 mol/L or more,and the upper limit of the concentration is preferably 2.5 mol/L orless, more preferably 2.0 mol/L or less, further more preferably 1.5mol/L or less. When the concentration is lower than 0.5 mol/L, there maybe caused a decrease in ionic conductance, leading to a decrease in thecycle characteristic and output characteristic of the non-aqueouselectrolyte battery. On the other hand, when the concentration exceeds2.5 mol/L, the viscosity of the electrolyte solution for a non-aqueouselectrolyte battery is increased, which may decrease the ionicconductance. Accordingly, there is a risk of lowering the cyclecharacteristic and the output characteristic of the non-aqueouselectrolyte battery.

When a large amount of the solute (s) is dissolved at once in anon-aqueous solvent, the liquid temperature may increase because of theheat of the dissolution of the solute(s). If the liquid temperatureincreases significantly, the decomposition of the fluorine-containingelectrolyte salt is accelerated and thus hydrogen fluoride may begenerated. Hydrogen fluoride causes deterioration in battery performanceand thus is not preferred. Although the liquid temperature at which thesolute(s) is dissolved in a non-aqueous solvent is not particularlylimited, the temperature ranges preferably −20° C. to 80° C., and morepreferably 0° C. to 60° C.

As stated above, the constitutional components to be contained in theelectrolyte solution for a non-aqueous electrolyte battery of thepresent invention have been explained. However, as long as the gist ofthe present invention is not impaired, any kinds of additives which havebeen generally used in an electrolyte solution for a non-aqueouselectrolyte battery may be added at any ratio to the electrolytesolution for a non-aqueous electrolyte battery of the present invention.Specific examples thereof include compounds having an effect ofpreventing overcharge, an effect of forming a negative electrode filmand an effect of protecting a positive electrode, such ascyclohexylbenzene, biphenyl, t-butylbenzene, vinylene carbonate, vinylethylene carbonate, difluoroanisole, fluoroethylene carbonate, propanesultone, succinonitrile and dimethyl vinylene carbonate. Moreover, asused in a non-aqueous electrolyte battery referred to as a lithiumpolymer battery, an electrolyte solution for a non-aqueous electrolytebattery can be pseudo-solidified with a gelling agent or a cross-linkedpolymer and then used.

Next, the structure or composition of the non-aqueous electrolytebattery of the present invention will be explained. The non-aqueouselectrolyte battery of the present invention is characterized by the useof the above electrolyte solution for a non-aqueous electrolyte batteryof the present invention. Any kinds of components which constitutenon-aqueous electrolyte batteries other than the present non-aqueouselectrolyte and which have been generally used in non-aqueouselectrolyte batteries may be also used for the present non-aqueouselectrolyte battery. Specifically, such components include a positiveelectrode and a negative electrode capable of occluding and releasingcations, a collector, a separator, and a container.

Materials for negative electrodes may not be particularly limited. Theyinclude, in the case of a lithium battery and a lithium ion battery, alithium metal, an alloy of a lithium metal and another metal, orintermetallic compounds, various kinds of carbon materials (e.g.,artificial graphite and natural graphite), a metal oxide, a metalnitride, tin (elemental substance), a tin compound, silicon (elementalsubstance), a silicon compound, an activated carbon, and a conductivepolymer.

Examples of carbon materials include easily graphitizable carbon, hardlygraphitizable carbon (hard carbon) having the interplanar spacing ofplane (002) of 0.37 nm or more, and graphite having the interplanarspacing of plane (002) of 0.34 nm or less. More specific examplesthereof include pyrolytic carbon, cokes, glassy carbon fibers, organicpolymer compound fired bodies, activated carbon or carbon black. Ofthese, cokes include a pitch coke, a needle coke or a petroleum coke. Anorganic polymer compound fired body is referred to as a product producedby burning a phenol resin, a furan resin or the like at an appropriatetemperature, followed by carbonization. Carbon materials are preferredsince the crystal structure remains almost unchanged after the occlusionand release of lithium, so that higher energy density and excellentcycle characteristic can be obtained. In addition, the shape of a carbonmaterial may be fibrous, spherical, granular or squamous. Furthermore,amorphous carbon or a graphite material whose surface is coated withamorphous carbon, is more preferred since the reactivity between thematerial surface and the electrolyte solution decreases.

Materials for positive electrodes to be used herein are not particularlylimited. In the case of a lithium battery and a lithium ion battery,there can be used lithium-containing transition metal composite oxidessuch as LiCoO₂, LiNiO₂, LiMnO₂, and LiMn₂O₄, those lithium-containingtransition metal composite oxides wherein a plurality of transitionmetals such as Co, Mn and Ni are mixed, those lithium-containingtransition metal composite oxides wherein a part of the transitionmetals is replaced with a metal other than the transition metals,phosphate compounds of transition metals referred to as olivine such asLiFePO₄, LiCoPO₄, and LiMnPO₄, oxides such as TiO₂, V₂O₅ and MoO₃,sulfides such as TiS₂ and FeS, or conducting polymers such aspolyacetylene, polyparaphenylene, polyaniline and polypyrrole, activatedcarbon, polymers that generate radicals, and carbon materials.

To a positive electrode or negative electrode material, acetylene black,Ketjen black, carbon fibers, or graphite as a conductive additive andpolytetrafluoroethylene, polyvinylidene fluoride, SBR resin, or the likeare added as a binder material, and then the resultant mixture is formedinto a sheet, so that an electrode sheet can be produced.

As a separator for preventing the contact between a positive electrodeand a negative electrode, a nonwoven fabric or porous sheet made ofpolypropylene, polyethylene, paper, and glass fibers is used.

A non-aqueous electrolyte battery formed to have a coin shape,cylindrical shape, square shape, laminated aluminum sheet form, or thelike is assembled with each of the above components.

EXAMPLES

The present invention will be more specifically explained with referenceto Examples, but the scope of the present invention is not limited tothese Examples.

Preparation of Non-Aqueous Electrolyte Solution

LiPF₆ as a solute was dissolved in a mixed solvent containing ethylenecarbonate, propylene carbonate, dimethyl carbonate and ethyl methylcarbonate at a volume ratio of 2:1:4:3 as a non-aqueous solvent, so thatthe concentration of the salute was set at 1.0 mol/L. Then, the compoundNo. 2 as the first compound was added to the mixed solvent so as toachieve a concentration of 0.5% by mass and a lithium salt of thecompound No. 15 as the second compound was added to the mixed solvent soas to achieve a concentration of 1.0% by mass, followed by stirring, toprepare an electrolyte solution No. 1. In this case, the abovepreparation was performed while maintaining the liquid temperature at25° C. Table 1 shows the conditions for preparation of the electrolytesolution No. 1.

Electrolyte solutions No. 2 to 129 were also prepared in the same manneras above, except that the type and the concentration of the firstcompound, the type and the concentration of the second compound, and thetype of the counter cation were changed as shown in Table 1 and Table 2.In this case, compounds No. 51 to 53 used as the first compound inpreparation of the electrolyte solutions No. 117 to 119 and anions ofthe compounds No. 54 to 63 used as the second compound in preparation ofthe electrolyte solutions No. 120 to 129 are shown.

Example 1-1

A cell was prepared using the electrolyte solution No. 1 as anon-aqueous electrolyte solution, LiNi_(1/3)Mn_(1/3)Co_(1/3)O₂ as apositive electrode material, and graphite as a negative electrodematerial. The cell was actually evaluated for a high-temperature cyclecharacteristic, a high-temperature storage characteristic, and alow-temperature output characteristic of the battery. A test cell wasprepared as follows.

LiNi_(1/3)Mn_(1/3)Co_(1/3)O₂ powder (90% by mass) was mixed with 5% bymass of polyvinylidene fluoride (PVDF) as a binder and 5% by mass ofacetylene black as a conductive additive. N-methylpyrrolidone wasfurther added to the mixture and then the resultant mixture was formedinto a paste. The paste was applied onto an aluminum foil, and then thefoil was dried, thereby preparing a positive electrode body for a test.Graphite powder (90% by mass) was mixed with 10% by mass of PVDF as abinder and then N-methylpyrrolidone was further added the resultantmixture to form a slurry. The slurry was applied onto a copper foil, andthen the foil was dried at 150° C. for 12 hours, thereby obtaining anegative electrode body for the test. A polyethylene separator wassoaked with the electrolyte solution, so as to assemble a 100 mAh cellarmored with an aluminum laminate.

A charge and discharge test was conducted using the cells prepared bythe above methods, and evaluation of high-temperature cyclecharacteristics, high-temperature storage characteristics, andlow-temperature output characteristics was performed by a methoddescribed below. Evaluation results are shown in Table 3.

High-Temperature Cycle Characteristic Test

A charge and discharge test was conducted at an ambient temperature of50° C. to evaluate a cycle characteristic. Charging was performed up to4.3 V, and discharging was performed to 3.0 V, and then a charge anddischarge cycle was repeated at a current density of 1.9 mA/cm². Thecells were evaluated for a degree of deterioration based on a dischargecapacity maintenance % after 200 cycles (evaluation of a cyclecharacteristic). The discharge capacity maintenance % was determined bythe following formula.

<Discharge Capacity Maintenance % after 200 Cycles>Discharge capacity maintenance (%)=(discharge capacity after 200cycles/initial discharge capacity)×100

The values of the discharge capacity maintenance % after 200 cyclesshown in Table 3 are values relative to the value of the dischargecapacity maintenance % after 200 cycles determined for Comparativeexample 1-1 designated as 100.

High-Temperature Storage Characteristic Test

After the cycle test, charging was performed by a constant voltage andconstant current method at an ambient temperature of 25° C. and acurrent density of 0.38 mA/cm² to an upper limit charging voltage of 4.3V, followed by storage at an ambient temperature of 50° C. for 10 days.Subsequently, discharging was performed with a constant current densityof 0.38 mA/cm² to a discharge end voltage of 3.0 V. The proportion of adischarge capacity to an initial discharge capacity (a value of adischarge capacity measured after the cycle test and before storage at50° C.) was defined as the remaining capacity proportion and was used toevaluate a storage characteristic of the cells. The values of aremaining capacity proportion shown in Table 3 are values relative tothe remaining capacity proportion determined for Comparative example 1-1designated as 100.

Low-Temperature Output Characteristic Test

After the storage test, charging was performed by a constant voltage andconstant current method at an ambient temperature of 25° C. and acurrent density of 0.38 mA/cm² to an upper limit charging voltage of 4.3V. Then, discharging was performed at an ambient temperature of −30° C.with a current density of 9.5 mA/cm² to a lower limit dischargingvoltage of 3.0 V. The average discharge voltage at this time wasmeasured. The values of the average discharge voltage shown in Table 2are values relative to the average discharge voltage determined forComparative example 1-1 designated as 100.

Examples 1-2 to 1-65, Comparative Examples 1-1 to 1-64

In the same manner as in Example 1-1, cells were prepared respectivelyusing the electrolyte solutions Nos. 2 to 129 instead of the electrolytesolution No. 1 and evaluated for a high-temperature cyclecharacteristic, high-temperature storage characteristic, andlow-temperature output characteristic. Evaluation results are shown inTable 3 and Table 4.

TABLE 1 First compound Second compound Com- Con- Com- Con- poundcentration pound Counter centration No. [% by mass] No. cation [% bymass] Electrolyte No. 2  0.5 No. 15 Li⁺ 1.0 solution No. 1 Electrolyte0.5 0.005 solution No. 2 Electrolyte 0.5 0.05 solution No. 3 Electrolyte0.5 0.1 solution No. 4 Electrolyte 0.5 0.5 solution No. 5 Electrolyte0.5 2.0 solution No. 6 Electrolyte 0.5 10.0 solution No. 7 Electrolyte1.0 1.0 solution No. 8 Electrolyte 0.005 1.0 solution No. 9 Electrolyte0.05 1.0 solution No. 10 Electrolyte 0.1 1.0 solution No. 11 Electrolyte2.0 1.0 solution No. 12 Electrolyte 10.0 1.0 solution No. 13 ElectrolyteNo. 1  0.5 1.0 solution No. 14 Electrolyte No. 3  0.5 1.0 solution No.15 Electrolyte No. 4  0.5 1.0 solution No. 16 Electrolyte No. 5  0.5 1.0solution No. 17 Electrolyte No. 6  0.5 1.0 solution No. 18 ElectrolyteNo. 7  0.5 1.0 solution No. 19 Electrolyte No. 8  0.5 1.0 solution No.20 Electrolyte No. 9  0.5 1.0 solution No. 21 Electrolyte No. 10 0.5 1.0solution No. 22 Electrolyte No. 11 0.5 1.0 solution No. 23 ElectrolyteNo. 12 0.5 1.0 solution No. 24 Electrolyte No. 13 0.5 1.0 solution No.25 Electrolyte No. 2  0.5 No. 14 1.0 solution No. 26 Electrolyte 0.5 No.16 1.0 solution No. 27 Electrolyte 0.5 No. 17 1.0 solution No. 28Electrolyte 0.5 No. 18 1.0 solution No. 29 Electrolyte 0.5 No. 19 1.0solution No. 30 Electrolyte 0.5 No. 20 1.0 solution No. 31 Electrolyte0.5 No. 21 1.0 solution No. 32 Electrolyte 0.5 No. 22 1.0 solution No.33 Electrolyte 0.5 No. 23 1.0 solution No. 34 Electrolyte 0.5 No. 24 1.0solution No. 35 Electrolyte 0.5 No. 25 1.0 solution No. 36 Electrolyte0.5 No. 26 1.0 solution No. 37 Electrolyte 0.5 No. 27 1.0 solution No.38 Electrolyte 0.5 No. 28 1.0 solution No. 39 Electrolyte 0.5 No. 29 1.0solution No. 40 Electrolyte 0.5 No. 30 1.0 solution No. 41 Electrolyte0.5 No. 31 1.0 solution No. 42 Electrolyte 0.5 No. 32 1.0 solution No.43 Electrolyte 0.5 No. 33 1.0 solution No. 44 Electrolyte 0.5 No. 34 1.0solution No. 45 Electrolyte 0.5 No. 35 1.0 solution No. 46 Electrolyte0.5 No. 36 1.0 solution No. 47 Electrolyte 0.5 No. 37 2Li⁺ 1.0 solutionNo. 48 Electrolyte 0.5 No. 38 1.0 solution No. 49 Electrolyte 0.5 No. 391.0 solution No. 50 Electrolyte 0.5 No. 40 1.0 solution No. 51Electrolyte 0.5 No. 41 1.0 solution No. 52 Electrolyte 0.5 No. 42 1.0solution No. 53 Electrolyte 0.5 No. 43 1.0 solution No. 54 Electrolyte0.5 No. 44 1.0 solution No. 55 Electrolyte 0.5 No. 45 1.0 solution No.56 Electrolyte 0.5 No. 46 1.0 solution No. 57 Electrolyte 0.5 No. 47 1.0solution No. 58 Electrolyte 0.5 No. 48 1.0 solution No. 59 Electrolyte0.5 No. 49 1.0 solution No. 60 Electrolyte 0.5 No. 50 1.0 solution No.61 Electrolyte 0.5 No. 15 Na⁺ 1.0 solution No. 62 Electrolyte 0.5 K⁺ 1.0solution No. 63 Electrolyte 0.5 (C₂H₅)₄N⁺ 1.0 solution No. 64Electrolyte 0.5 (C₂H₅)₄P⁺ 1.0 solution No. 65

TABLE 2 First compound Second compound Com- Con- Com- Con- poundcentration pound Counter centration No. [% by mass] No. cation [% bymass] Electrolyte None — None — — solution No. 66 Electrolyte No. 1  0.5— solution No. 67 Electrolyte No. 2  0.5 — solution No. 68 ElectrolyteNo. 3  0.5 — solution No. 69 Electrolyte No. 4  0.5 — solution No. 70Electrolyte No. 5  0.5 — solution No. 71 Electrolyte No. 6  0.5 —solution No. 72 Electrolyte No. 7  0.5 — solution No. 73 Electrolyte No.8  0.5 — solution No. 74 Electrolyte No. 9  0.5 — solution No. 75Electrolyte No. 10 0.5 — solution No. 76 Electrolyte No. 11 0.5 —solution No. 77 Electrolyte No. 12 0.5 — solution No. 78 Electrolyte No.13 0.5 — solution No. 79 Electrolyte None — No. 14 Li⁺ 1.0 solution No.80 Electrolyte — No. 15 1.0 solution No. 81 Electrolyte — No. 16 1.0solution No. 82 Electrolyte — No. 17 1.0 solution No. 83 Electrolyte —No. 18 1.0 solution No. 84 Electrolyte — No. 19 1.0 solution No. 85Electrolyte — No. 20 1.0 solution No. 86 Electrolyte — No. 21 1.0solution No. 87 Electrolyte — No. 22 1.0 solution No. 88 Electrolyte —No. 23 1.0 solution No. 89 Electrolyte — No. 24 1.0 solution No. 90Electrolyte — No. 25 1.0 solution No. 91 Electrolyte — No. 26 1.0solution No. 91 Electrolyte — No. 27 1.0 solution No. 93 Electrolyte —No. 28 1.0 solution No. 94 Electrolyte — No. 29 1.0 solution No. 95Electrolyte — No. 30 1.0 solution No. 96 Electrolyte — No. 31 1.0solution No. 97 Electrolyte — No. 32 1.0 solution No. 98 Electrolyte —No. 33 1.0 solution No. 99 Electrolyte — No. 34 1.0 solution No. 100Electrolyte — No. 35 1.0 solution No. 101 Electrolyte — No. 36 1.0solution No. 102 Electrolyte — No. 37 2Li⁺ 1.0 solution No. 103Electrolyte — No. 38 1.0 solution No. 104 Electrolyte — No. 39 1.0solution No. 105 Electrolyte — No. 40 1.0 solution No. 106 Electrolyte —No. 41 1.0 solution No. 107 Electrolyte — No. 42 1.0 solution No. 108Electrolyte — No. 43 1.0 solution No. 109 Electrolyte — No. 44 1.0solution No. 110 Electrolyte — No. 45 1.0 solution No. 111 Electrolyte —No. 46 1.0 solution No. 112 Electrolyte — No. 47 1.0 solution No. 113Electrolyte — No. 48 1.0 solution No. 114 Electrolyte — No. 49 1.0solution No. 115 Electrolyte — No. 50 1.0 solution No. 116 ElectrolyteNo. 51 0.5 No. 15 Li⁺ 1.0 solution No. 117 Electrolyte No. 52 0.5 1.0solution No. 118 Electrolyte No. 53 0.5 1.0 solution No. 119 ElectrolyteNo. 2  0.5 No. 54 1.0 solution No. 120 Electrolyte 0.5 No. 55 1.0solution No. 121 Electrolyte 0.5 No. 56 1.0 solution No. 122 Electrolyte0.5 No. 57 2Li⁺ 1.0 solution No. 123 Electrolyte 0.5 No. 58 Li⁺ 1.0solution No. 124 Electrolyte 0.5 No. 59 1.0 solution No. 125 Electrolyte0.5 No. 60 1.0 solution No. 126 Electrolyte 0.5 No. 61 2Li⁺ 1.0 solutionNo. 127 Electrolyte 0.5 No. 62 1.0 solution No. 128 Electrolyte 0.5 No.63 1.0 solution No. 129

TABLE 3 Discharge Positive Negative capacity Remaining AverageElectrolyte electrode electrode maintenance* capacity discharge solutionActive Active [%] After proportion* voltage* No. material material 200cycles [%] [%] Example No.1 LiNi_(1/3)Mn_(1/3)Co_(1/3)O₂ Graphite 138151 106 1-1 Example No.2 122 143 103 1-2 Example No.3 124 144 104 1-3Example No.4 130 146 105 1-4 Example No.5 135 149 105 1-5 Example No.6132 139 106 1-6 Example No.7 123 137 105 1-7 Example No.8 137 151 1051-8 Example No.9 105 107 103 1-9 Example No.10 110 111 104 1-10 ExampleNo.11 113 115 104 1-11 Example No.12 137 149 104 1-12 Example No.13 133140 103 1-13 Example No.14 130 137 105 1-14 Example No.15 132 136 1061-15 Example No.16 127 133 105 1-16 Example No.17 125 130 105 1-17Example No.18 129 133 104 1-18 Example No.19 137 150 105 1-19 ExampleNo.20 131 134 104 1-20 Example No.21 130 134 104 1-21 Example No.22 130133 104 1-22 Example No.23 129 133 104 1-23 Example No.24 129 132 1041-24 Example No.25 129 130 103 1-25 Example No.26 126 129 104 1-26Example No.27 136 147 104 1-27 Example No.28 135 147 104 1-28 ExampleNo.29 133 145 104 1-29 Example No.30 133 144 103 1-30 Example No.31 135146 104 1-31 Example No.32 136 145 105 1-32 Example No.33 130 131 1031-33 Example No.34 131 131 103 1-34 Example No.35 127 129 104 1-35Example No.36 135 146 103 1-36 Example No.37 128 127 104 1-37 ExampleNo.38 127 128 103 1-38 Example No.39 127 130 103 1-39 Example No.40 126130 103 1-40 Example No.41 127 131 103 1-41 Example No.42 121 114 1021-42 Example No.43 126 128 103 1-43 Example No.44 112 110 102 1-44Example No.45 113 112 103 1-45 Example No.46 113 111 102 1-46 ExampleNo.47 108 105 102 1-47 Example No.48 137 149 104 1-48 Example No.49 128130 103 1-49 Example No.50 127 130 102 1-50 Example No.51 122 115 1021-51 Example No.52 125 127 103 1-52 Example No.53 120 113 102 1-53Example No.54 105 105 102 1-54 Example No.55 107 106 102 1-55 ExampleNo.56 107 107 102 1-56 Example No.57 123 127 104 1-57 Example No.58 108109 102 1-58 Example No.59 107 108 104 1-59 Example No.60 110 109 1031-60 Example No.61 103 103 102 1-61 Example No.62 130 149 106 1-62Example No.63 130 150 106 1-63 Example No.64 129 151 105 1-64 ExampleNo.65 128 150 105 1-65 *Relative value when the value of Comparativeexample 1-1 is designated as 100.

TABLE 4 Discharge Positive Negative capacity Remaining AverageElectrolyte electrode electrode maintenance* capacity discharge solutionActive Active [%] After proportion* voltage No. material material 200cycles [%] [%] Comparative No.66 LiNi_(1/3)Mn_(1/3)Co_(1/3)O₂ Graphite100 100 100 example 1-1 Comparative No.67 95 93 97 example 1-2Comparative No.68 100 99 96 example 1-3 Comparative No.69 98 98 95example 1-4 Comparative No.70 95 94 95 example 1-5 Comparative No.71 9291 95 example 1-6 Comparative No.72 94 92 94 example 1-7 ComparativeNo.73 99 100 94 example 1-8 Comparative No.74 98 97 97 example 1-9Comparative No.75 96 96 97 example 1-10 Comparative No.76 97 96 97example 1-11 Comparative No.77 96 97 97 example 1-12 Comparative No.7894 95 96 example 1-13 Comparative No.79 92 92 95 example 1-14Comparative No.80 104 97 98 example 1-15 Comparative No.81 102 91 100example 1-16 Comparative No.82 102 93 98 example 1-17 Comparative No.83103 94 97 example 1-18 Comparative No.84 102 90 97 example 1-19Comparative No.85 101 88 97 example 1-20 Comparative No.86 101 90 99example 1-21 Comparative No.87 102 96 96 example 1-22 Comparative No.88103 97 96 example 1-23 Comparative No.89 102 92 96 example 1-24Comparative No.90 101 89 96 example 1-25 Comparative No.91 101 90 99example 1-26 Comparative No.92 102 92 97 example 1-27 Comparative No.93102 93 96 example 1-28 Comparative No.94 103 94 97 example 1-29Comparative No.95 104 93 97 example 1-30 Comparative No.96 104 92 96example 1-31 Comparative No.97 103 87 96 example 1-32 Comparative No.98102 93 97 example 1-33 Comparative No.99 103 94 96 example 1-34Comparative No.100 102 95 96 example 1-35 Comparative No.101 102 93 96example 1-36 Comparative No.102 103 92 96 example 1-37 ComparativeNo.103 104 97 99 example 1-38 Comparative No.104 103 95 97 example 1-39Comparative No.105 102 96 97 example 1-40 Comparative No.106 101 93 97example 1-41 Comparative No.107 101 92 97 example 1-42 ComparativeNo.108 101 89 96 example 1-43 Comparative No.109 102 90 96 example 1-44Comparative No.110 102 93 96 example 1-45 Comparative No.111 101 92 96example 1-46 Comparative No.112 102 94 97 example 1-47 ComparativeNo.113 102 94 96 example 1-48 Comparative No.114 101 90 96 example 1-49Comparative No.115 101 88 96 example 1-50 Comparative No.116 101 90 96example 1-51 Comparative No.117 99 100 94 example 1-52 ComparativeNo.118 71 82 96 example 1-53 Comparative No.119 93 89 97 example 1-54Comparative No.120 100 95 98 example 1-55 Comparative No.121 101 88 99example 1-56 Comparative No.122 100 94 97 example 1-57 ComparativeNo.123 102 91 97 example 1-58 Comparative No.124 100 85 95 example 1-59Comparative No.125 101 91 95 example 1-60 Comparative No.126 102 87 94example 1-61 Comparative No.127 101 89 95 example 1-62 ComparativeNo.128 102 93 96 example 1-63 Comparative No.129 102 93 96 example 1-64*Relative value when the value of Comparative example 1-1 is designatedas 100.

The above results confirm that a high-temperature cycle characteristic,high-temperature storage characteristic, and low-temperature outputcharacteristic are improved by combining the first compound with thesecond compound, as compared with Comparative examples 1-2 to 1-14wherein the first compound was used alone. Similarly, the above resultsconfirm that a high-temperature cycle characteristic, high-temperaturestorage characteristic, and low-temperature output characteristic wereimproved by combining the first compound with the second compound, ascompared with Comparative examples 1-15 to 1-51 wherein the secondcompound was used alone.

In the case of Comparative examples 1-52 and 1-53 wherein R² of thefirst compound represented by general formula (1) is not a linear orbranched C₁₋₁₀ alkyl group (R² in Comparative example 1-52 contained afluorine group, and R² in Comparative example 1-53 contained a methoxygroup), a low-temperature output characteristic was decreased and noimprovement was confirmed in a high-temperature cycle characteristic orhigh-temperature storage characteristic. In the case of Comparativeexample 1-54 wherein the number of groups having a carbon-carbonunsaturated bond is 1 or less, no improvement was confirmed in ahigh-temperature cycle characteristic, high-temperature storagecharacteristic, or low-temperature output characteristic.

In the case of Comparative examples 1-55 to 1-58 wherein the secondcompound contains neither a P—F bond nor an S—F bond, no improvement wasconfirmed in a high-temperature cycle characteristic, high-temperaturestorage characteristic, or low-temperature output characteristic. In thecase of Comparative examples 1-59 to 1-64 wherein the second compoundcontains a P—F bond or an S—F bond but does not have a structure whosesubstituent bonded to a P atom is a hydrocarbon group containing anintervening oxygen atom (such as an alkoxy group) and has a structurehaving a hydrocarbon group containing no intervening oxygen atom (suchas an alkyl group), a low-temperature output characteristic wasdecreased and no improvement was confirmed in a high-temperature cyclecharacteristic or high-temperature storage characteristic.

The evaluation results will be explained below for the electrolytesolutions containing a typical first compound and a typical secondcompound in combination at a typical concentration also changing thetypes of positive electrodes, the types of negative electrodes, and thetypes of counter cations of the second compound. The tendencies similarto those as explained above were confirmed for the electrolyte solutionswherein the combinations of the first compound and the second compoundand the concentrations thereof are different from those which will bedescribed below.

Examples 2-1 to 2-43 and Comparative Examples 2-1 to 2-20

In Examples 2-1 to 2-43 and Comparative examples 2-1 to 2-20, as shownin Table 6, electrolyte solutions for non-aqueous electrolyte batterieswere prepared, cells were prepared, and then the batteries wereevaluated in the same manner as Example 1-1 except that the kinds of thenegative electrode bodies and the kinds of the electrolyte solutionswere changed. In this case, in Examples 2-1 to 2-13 and Comparativeexamples 2-1 to 2-5 wherein the negative electrode active material isLi₄Ti₅O₁₂, the negative electrode bodies were prepared by mixing 90% bymass of Li₄Ti₅O₁₂ powder with 5% by mass of PVDF as a binder and 5% bymass of acetylene black as a conductive additive, to whichN-methylpyrrolidone was added, applying the thus obtained paste onto acopper foil, and then drying it. The charge end voltage was 2.8 V andthe discharge end voltage was 1.5 V, when the batteries were evaluated.Furthermore, in Examples 2-14 to 2-30 and Comparative examples 2-6 to2-15 wherein the negative electrode active material was graphite(containing silicon), the negative electrode body was prepared by mixing81% by mass of graphite powder and 9% by mass of silicon powder with 5%by mass of PVDF as a binder and 5% by mass of acetylene black as aconductive additive, to which N-methylpyrrolidone was added, applyingthe thus obtained paste onto a copper foil, and then drying it. Thecharge end voltage and the discharge end voltage when the batteries wereevaluated were the same as those in Example 1-1. Moreover, in Examples2-31 to 2-43 and Comparative examples 2-16 to 2-20 wherein the negativeelectrode active material was hard carbon, the negative electrode bodywas prepared by mixing 90% by mass of hard carbon powder with 5% by massof PVDF as a binder and 5% by mass of acetylene black as a conductiveadditive, to which N-methylpyrrolidone was added, applying the thusobtained paste onto a copper foil, and then drying it. The charge endvoltage and the discharge end voltage when the batteries were evaluatedwere 4.2 V and 2.2 V, respectively.

The electrolyte solution used in Example 2-27 was prepared as follows. Amixed solvent containing ethylene carbonate, fluoroethylene carbonate,dimethyl carbonate, and ethyl methyl carbonate at a volume ratio of2.5:0.5:4:3 was used as a non-aqueous solvent. LiPF₆ as a solute wasdissolved in the solvent to achieve a concentration of 1.0 mol/L. Then,the compound No. 2 as the first compound was added to the resultantsolution so as to achieve a concentration of 0.5% by mass and a lithiumsalt of the compound No. 15 as the second compound was added to theresultant solution so as to achieve a concentration of 1.0% by mass,followed by stirring, to prepare an electrolyte solution No. 130. Theabove preparation was performed while maintaining the liquid temperatureat 25° C. Table 5 shows the conditions for preparation of theelectrolyte solution No. 130. The electrolyte solutions No. 131 to 138were also prepared in the same manner as the electrolyte solution No.130, except that the kinds and the like of the first compound and thesecond compound were changed as shown in Table 5.

The evaluation results for a high-temperature cycle characteristic,high-temperature storage characteristic and low-temperature outputcharacteristic are shown in Table 6. The evaluation results (the valuesof discharge capacity maintenance % after 200 cycles, the values ofremaining capacity proportion, the values of average discharge voltage)of Examples 2-1 to 2-26, Examples 2-31 to 2-43, Comparative examples 2-1to 2-10, and Comparative examples 2-16 to 2-20 in Table 6 are valuesrelative to the evaluation results in the Comparative examples using theelectrolyte solution No. 66 designated as 100 in respect of eachelectrode constitution. The evaluation results (the values of dischargecapacity maintenance % after 200 cycles, the values of remainingcapacity proportion, the values of average discharge voltage) ofExamples 2-27 to 2-30 and Comparative examples 2-11 to 2-15 in Table 6are values relative to the evaluation results in the Comparativeexamples using the electrolyte solution No. 134 designated as 100.

TABLE 5 First compound Second compound Com- Con- Com- Con- poundcentration pound Counter centration No. [% by mass] No. cation [% bymass] Electrolyte No. 2 0.5 No. 15 Li⁺ 1.0 solution No. 130 ElectrolyteNo. 7 0.5 1.0 solution No. 131 Electrolyte No. 2 0.5 No. 14 1.0 solutionNo. 132 Electrolyte No. 7 0.5 1.0 solution No. 133 Electrolyte None —None — — solution No. 134 Electrolyte No. 2 0.5 — solution No. 135Electrolyte No. 7 0.5 — solution No. 136 Electrolyte None — No. 15 Li⁺1.0 solution No. 137 Electrolyte — No. 14 1.0 solution No. 138

TABLE 6 Discharge Positive Negative capacity Remaining AverageElectrolyte electrode electrode maintenance* capacity discharge solutionActive Active [%] After proportion* voltage No. material material 200cycles [%] [%] Example 2-1 No.1 LiNi_(1/3)Mn_(1/3)Co_(1/3)O₂ Li₄Ti₅O₁₂119 125 105 Example 2-2 No.19 119 124 105 Example 2-3 No.26 113 114 103Example 2-4 No.28 118 123 104 Example 2-5 No.36 117 123 103 Example 2-6No.38 114 114 102 Example 2-7 No.40 113 114 102 Example 2-8 No.43 112113 102 Example 2-9 No.46 106 105 103 Example No.48 108 123 104 2-10Example No.52 113 113 104 2-11 Example No.57 112 114 103 2-12 ExampleNo.61 102 101 102 2-13 Comparative No.66 100 100 100 example 2-1Comparative No.68 99 99 97 example 2-2 Comparative No.81 102 95 99example 2-3 Comparative No.117 100 99 96 example 2-4 Comparative No.12196 94 100 example 2-5 Example No.1 Graphite 133 145 105 2-14 (containingExample No.19 silicon) 132 145 104 2-15 Example No.26 122 124 103 2-16Example No.28 130 141 103 2-17 Example No.36 131 141 103 2-18 ExampleNo.38 122 123 102 2-19 Example No.40 122 124 103 2-20 Example No.43 121124 102 2-21 Example No.46 106 106 103 2-22 Example No.48 132 144 1052-23 Example No.52 121 122 104 2-24 Example No.57 119 121 103 2-25Example No.61 101 102 102 2-26 Example No.130 132 146 105 2-27 ExampleNo.131 130 145 104 2-28 Example No.132 121 124 102 2-29 Example No.133120 122 101 2-30 Comparative No.66 100 100 100 example 2-6 ComparativeNo.68 98 97 97 example 2-7 Comparative No.81 101 89 98 example 2-8Comparative No.117 97 100 96 example 2-9 Comparative No.121 94 91 100example 2-10 Comparative No.134 100 100 100 example 2-11 ComparativeNo.135 99 98 96 example 2-12 Comparative No.136 98 99 93 example 2-13Comparative No.137 102 93 98 example 2-14 Comparative No.138 103 97 96example 2-15 Example No.1 Hard 129 141 105 2-31 carbon Example No.19 127140 105 2-32 Example No.26 117 120 104 2-33 Example No.28 126 137 1032-34 Example No.36 125 136 103 2-35 Example No.38 118 118 103 2-36Example No.40 116 120 102 2-37 Example No.43 116 119 102 2-38 ExampleNo.46 105 104 104 2-39 Example No.48 126 139 104 2-40 Example No.52 114118 103 2-41 Example No.57 114 117 103 2-42 Example No.61 102 102 1032-43 Comparative No.66 100 100 100 example 2-16 Comparative No.68 99 10098 example 2-17 Comparative No.81 102 92 99 example 2-18 ComparativeNo.117 99 99 97 example 2-19 Comparative No.121 96 91 99 example 2-20*Relative value in each corresponding battery configuration, when thevalue of Comparative example wherein Electrolyte solution No. 66 wasused is designated as 100.(In Examples 2-27 to 2-30 and Comparative examples 2-11 to 2-15, therelative value when the value of Comparative example 2-11 is designatedas 100.)

Examples 3-1 to 3-52 and Comparative Examples 3-1 to 3-20

In Examples 3-1 to 3-52 and Comparative examples 3-1 to 3-20, as shownin Tables 7 and 8, the electrolyte solutions for non-aqueous electrolytebatteries were prepared, cells were prepared, and then the batterieswere evaluated in the same manner as in Example 1-1, except that thekinds of the positive electrode bodies and the negative electrodebodies, as well as the kinds of the electrolyte solutions were changed.In this case, the positive electrode body wherein the positive electrodeactive material is LiCoO₂ was prepared by mixing 90% by mass of LiCoO₂powder with 5% by mass of PVDF as a binder and 5% by mass of acetyleneblack as a conductive additive, to which N-methylpyrrolidone was added,applying the thus obtained paste onto an aluminum foil, and then dryingit. In Examples 3-1 to 3-13 and Comparative examples 3-1 to 3-5 whereinthe negative electrode active material is graphite as in Example 1-1,the charge end voltage was 4.2 V and the discharge end voltage was 3.0V, when the resultant batteries were evaluated. In Examples 3-14 to 3-26and Comparative examples 3-6 to 3-10 wherein the negative electrodeactive material is Li₄Ti₅O₁₂ as in Example 2-1, the charge end voltagewas 2.7V and the discharge end voltage was 1.5 V, when the resultantbatteries were evaluated. In Examples 3-27 to 3-39 and Comparativeexamples 3-11 to 3-15 wherein the negative electrode active material isgraphite (containing silicon at 9% by mass) as in Example 2-14, thecharge end voltage was 4.2 V and the discharge end voltage was 3.0 V,when the resultant batteries were evaluated. In Examples 3-40 to 3-52and Comparative examples 3-16 to 3-20 wherein the negative electrodeactive material is hard carbon as in Example 2-31, the charge endvoltage was 4.1 V and the discharge end voltage was 2.2 V, the resultantbatteries were evaluated. The evaluation results for a high-temperaturecycle characteristic, high-temperature storage characteristic andlow-temperature output characteristic are shown in Tables 7 and 8. Theevaluation results (the values of discharge capacity maintenance % after200 cycles, the values of remaining capacity proportion, the values ofaverage discharge voltage) in Tables 7 and 8 are values relative to theevaluation results of the Comparative examples using the electrolytesolution No. 66 designated as 100 in respect of each electrodeconstitution.

TABLE 7 Discharge Positive Negative capacity Remaining AverageElectrolyte electrode electrode maintenance* capacity discharge solutionActive Active [%] After proportion* voltage No. material material 200cycles [%] [%] Example 3-1 No.1 LiCoO₂ Graphite 137 149 105 Example 3-2No.19 136 149 104 Example 3-3 No.26 124 128 104 Example 3-4 No.28 133147 103 Example 3-5 No.36 134 145 103 Example 3-6 No.38 127 127 103Example 3-7 No.40 125 129 102 Example 3-8 No.43 124 127 103 Example 3-9No.46 111 110 103 Example No.48 136 148 105 3-10 Example No.52 124 126104 3-11 Example No.57 122 126 103 3-12 Example No.61 103 102 102 3-13Comparative No.66 100 100 100 example 3-1 Comparative No.68 99 99 98example 3-2 Comparative No.81 102 90 100 example 3-3 Comparative No.117100 98 97 example 3-4 Comparative No.121 94 89 99 example 3-5 ExampleNo.1 Li₄Ti₅O₁₂ 120 124 104 3-14 Example No.19 119 123 104 3-15 ExampleNo.26 112 112 102 3-16 Example No.28 117 122 103 3-17 Example No.36 117121 103 3-18 Example No.38 113 114 102 3-19 Example No.40 113 113 1023-20 Example No.43 111 112 103 3-21 Example No.46 105 103 102 3-22Example No.48 117 122 104 3-23 Example No.52 112 111 103 3-24 ExampleNo.57 111 112 103 3-25 Example No.61 102 102 103 3-26 Comparative No.66100 100 100 example 3-6 Comparative No.68 100 98 97 example 3-7Comparative No.81 101 94 98 example 3-8 Comparative No.117 99 100 97example 3-9 Comparative No.121 94 94 99 example 3-10 Example No.1Graphite 131 144 105 3-27 (containing Example No.19 silicon) 130 143 1043-28 Example No.26 120 123 103 3-29 Example No.28 129 140 103 3-30Example No.36 130 140 103 3-31 Example No.38 122 122 102 3-32 ExampleNo.40 121 121 102 3-33 Example No.93 120 122 103 3-34 Example No.46 105106 103 3-35 Example No.48 130 142 103 3-36 Example No.52 120 121 1043-37 Example No.57 117 120 102 3-38 Example No.61 102 101 102 3-39Comparative No.66 100 100 100 example 3-11 Comparative No.68 98 97 98example 3-12 Comparative No.81 102 88 98 example 3-13 Comparative No.11798 99 96 example 3-14 Comparative No.121 95 92 100 example 3-15*Relative value in each corresponding battery configuration, when thevalue of Comparative example wherein Electrolyte solution No. 66 wasused is designated as 100.

TABLE 8 Discharge Positive Negative capacity Remaining AverageElectrolyte electrode electrode maintenance* capacity discharge solutionActive Active [%] After proportion* voltage No. material material 200cycles [%] [%] Example No.1 LiCoO₂ Hard 128 140 104 3-40 carbon ExampleNo.19 127 139 104 3-41 Example No.26 115 119 102 3-42 Example No.28 125135 103 3-43 Example No.36 124 135 103 3-44 Example No.38 117 118 1033-45 Example No.40 115 118 102 3-46 Example No.43 115 118 102 3-47Example No.46 105 104 103 3-48 Example No.48 125 138 104 3-49 ExampleNo.52 114 117 103 3-50 Example No.57 113 115 102 3-51 Example No.61 101101 102 3-52 Comparative No.66 100 100 100 example 3-16 ComparativeNo.68 98 99 98 example 3-17 Comparative No.81 103 93 99 example 3-18Comparative No.117 98 99 97 example 3-19 Comparative No.121 97 92 100example 3-20 *Relative value in each corresponding batteryconfiguration, when the value of Comparative example wherein Electrolytesolution No. 66 was used is designated as 100.

Examples 4-1 to 4-39 and Comparative Examples 4-1 to 4-15

In Examples 4-1 to 4-39 and Comparative examples 4-1 to 4-15, as shownin Table 9, the electrolyte solutions for non-aqueous electrolytebatteries were prepared, cells were prepared, and then the batterieswere evaluated in the same manner as in Example 1-1, except that thekinds of the positive electrode bodies and the kinds of the electrolytesolutions were changed. In this case, in Examples 4-1 to 4-13 andComparative examples 4-1 to 4-5 wherein the positive electrode activematerial is LiNi_(0.8)Co_(0.15)Al_(0.05)O₂, the positive electrode bodywas prepared by mixing 90% by mass of LiNi_(0.8)Co_(0.15)Al_(0.05)O₂powder with 5% by mass of PVDF as a binder and 5% by mass of acetyleneblack as a conductive additive, to which N-methylpyrrolidone was added,applying the thus obtained paste onto an aluminum foil, and then dryingit. The charge end voltage and the discharge end voltage when theresultant batteries were evaluated were 4.3 V and 3.0 V, respectively.In Examples 4-14 to 4-26 and Comparative examples 4-6 to 4-10 whereinthe positive electrode active material is LiMn₂O₄, the positiveelectrode body was prepared by mixing 90% by mass of LiMn₂O₄ powder with5% by mass of PVDF as a binder and 5% by mass of acetylene black as aconductive additive, to which N-methylpyrrolidone was added, applyingthe thus obtained paste onto an aluminum foil, and then drying it. Thecharge end voltage and the discharge end voltage when the resultantbatteries were evaluated were 4.2 V and 3.0 V, respectively. In Examples4-27 to 4-39 and Comparative examples 4-11 to 4-15 wherein the positiveelectrode active material is LiFePO₄, the positive electrode body wasprepared by mixing 90% by mass of LiFePO₄ powder coated with amorphouscarbon, with 5% by mass of PVDF as a binder and 5% by mass of acetyleneblack as a conductive additive, to which N-methylpyrrolidone was added,applying the thus obtained paste onto an aluminum foil, and then dryingit. The charge end voltage and the discharge end voltage when theresultant batteries were evaluated were 4.2 V and 2.5 V, respectively.The evaluation results of a high-temperature cycle characteristic,high-temperature storage characteristic and low-temperature outputcharacteristic are shown in Table 9. The evaluation results (the valuesof discharge capacity maintenance % after 200 cycles, the values ofremaining capacity proportion, the values of average discharge voltage)in Table 9 are values relative to the evaluation results in theComparative examples using the electrolyte solution No. 66 designated as100 in respect of each electrode constitution.

TABLE 9 Discharge Positive Negative capacity Remaining AverageElectrolyte electrode electrode maintenance* capacity discharge solutionActive Active [%] After proportion* voltage* No. material material 200cycles [%] [%] Example 4-1 No.1 LiNi_(0.8)Co_(0.15)Al_(0.05)O₂ Graphite134 147 106 Example 4-2 No.19 133 145 105 Example 4-3 No.26 121 123 104Example 4-4 No.28 130 141 104 Example 4-5 No.36 130 140 103 Example 4-6No.38 121 123 103 Example 4-7 No.40 121 125 103 Example 4-8 No.43 120123 102 Example 4-9 No.46 109 107 103 Example No.48 131 144 103 4-10Example No.52 120 122 104 4-11 Example No.57 117 122 103 4-12 ExampleNo.61 103 103 103 4-13 Comparative No.66 100 100 100 example 4-1Comparative No.68 99 99 97 example 4-2 Comparative No.81 101 91 100example 4-3 Comparative No.117 99 100 97 example 4-4 Comparative No.12194 88 100 example 4-5 Example No.1 LiMn₂O₄ Graphite 130 135 105 4-14Example No.19 128 133 104 4-15 Example No.26 118 115 103 4-16 ExampleNo.28 126 131 103 4-17 Example No.36 125 131 102 4-18 Example No.38 119113 102 4-19 Example No.40 117 115 103 4-20 Example No.43 118 114 1034-21 Example No.46 108 108 103 4-22 Example No.48 129 134 104 4-23Example No.52 117 112 103 4-24 Example No.57 115 113 102 4-25 ExampleNo.61 104 105 102 1-26 Comparative No.66 100 100 100 example 4-6Comparative No.68 98 99 98 example 4-7 Comparative No.81 102 92 99example 4-8 Comparative No.117 100 98 96 example 4-9 Comparative No.12195 93 100 example 4-10 Example No.1 LiFePO₄ Graphite 120 126 103 4-27Example No.19 118 125 103 4-28 Example No.26 114 114 103 4-29 ExampleNo.28 117 123 102 4-30 Example No.36 117 122 102 4-31 Example No.38 113114 102 4-32 Example No.40 112 115 102 4-33 Example No.43 113 116 1024-34 Example No.46 110 108 102 4-35 Example No.48 119 123 103 4-36Example No.52 113 114 103 4-37 Example No.57 111 114 102 4-38 ExampleNo.61 104 103 102 4-39 Comparative No.66 100 100 100 example 4-11Comparative No.68 100 98 99 example 4-12 Comparative No.81 103 96 100example 4-13 Comparative No.117 98 98 98 example 4-14 Comparative No.12196 94 99 example 4-15 *Relative value in each corresponding batteryconfiguration, when the value of Comparative example wherein Electrolytesolution No. 66 was used is designated as 100.

As shown in the above, the results confirm that a high-temperature cyclecharacteristic, high-temperature storage characteristic, andlow-temperature output characteristic were improved in any of Exampleswhere the electrolyte solution for a non-aqueous electrolyte battery ofthe present invention was used and the negative electrode activematerial is any of Li₄Ti₅O₁₂, graphite (containing silicon) and hardcarbon, as compared with the corresponding Comparative examples. Thus,it was shown that the use of the electrolyte solution for a non-aqueouselectrolyte battery of the present invention provides an excellenthigh-temperature cycle characteristic, excellent high-temperaturestorage characteristic, and excellent low-temperature outputcharacteristic, regardless of the kinds of the negative electrode activematerials.

The results also confirm that a high-temperature cycle characteristic,high-temperature storage characteristic and low-temperature outputcharacteristic were improved in any of Examples where the electrolytesolution for a non-aqueous electrolyte battery of the present inventionwas used and the positive electrode active material is any of LiCoO₂,LiNi_(0.8)Co_(0.15)Al_(0.05)O₂, LiMn₂O₄ and LiFePO₄, as compared withthe corresponding Comparative examples. Thus, it was shown that the useof the electrolyte solution for a non-aqueous electrolyte battery of thepresent invention provides an excellent high-temperature cyclecharacteristic, excellent high-temperature storage characteristic andexcellent low-temperature output characteristic, regardless of the kindsof the positive electrode active materials.

Example 5-1

A mixed solvent containing ethylene carbonate and diethyl carbonate at avolume ratio of 1:1 was used as a non-aqueous solvent. NaPF₆ as a solutewas dissolved in the solvent so as to achieve a concentration of 1.0mol/L. Then, the compound No. 2 as the first compound was added to theresultant solution, so as to achieve a concentration of 0.5% by mass anda sodium salt of the compound No. 15 as the second compound was added tothe resultant solution so as to achieve a concentration of 1.0% by mass,followed by stirring, to prepare an electrolyte solution No. 139. Table10 shows the conditions for preparation of the electrolyte solution No.139.

Cells were produced using this electrolyte solution in the same manneras in Example 1-1, except that NaFe_(0.5)Co_(0.5)O₂ was used as apositive electrode material and hard carbon was used as a negativeelectrode material. The resultant batteries were evaluated for ahigh-temperature cycle characteristic, high-temperature storagecharacteristic and low-temperature output characteristic in the samemanner as in Example 1-1. In this case, the positive electrode bodywherein the positive electrode active material is NaFe_(0.5)Co_(0.5)O₂was prepared by mixing 90% by mass of NaFe_(0.5)Co_(0.5)O₂ powder, 5% bymass of PVDF as a binder, and 5% by mass of acetylene black as aconductive additive, to which N-methylpyrrolidone was added, applyingthe thus obtained paste onto an aluminum foil, and then drying it. Thecharge end voltage and the discharge end voltage when the batteries wereevaluated were 3.8 V and 1.5 V, respectively. The evaluation results areshown in Table 11.

Examples 5-2 to 5-13 and Comparative Examples 5-1 to 5-6

In Examples 5-2 to 5-13 and Comparative examples 5-1 to 5-6, as shown inTable 10, electrolyte solutions for non-aqueous electrolyte batterieswere prepared, cells were prepared, and then the batteries wereevaluated in the same manner as in Example 5-1, except that kinds of thefirst compounds and second compounds were changed. The evaluationresults of a high-temperature cycle characteristic, high-temperaturestorage characteristic and low-temperature output characteristic areshown in Table 11. The evaluation results (the values of dischargecapacity maintenance % after 200 cycles, the values of remainingcapacity proportion, the values of average discharge voltage) in Table11 are values relative to the evaluation results in Comparative example5-1 designated as 100.

TABLE 10 First compound Second compound Com- Con- Com- Con- poundcentration pound Counter centration No. [% by mass] No. cation [% bymass] Electrolyte No. 2  0.5 No. 15 Na⁺ 1.0 solution No. 139 ElectrolyteNo. 7  0.5 1.0 solution No. 140 Electrolyte No. 2  0.5 No. 14 1.0solution No. 141 Electrolyte 0.5 No. 17 1.0 solution No. 142 Electrolyte0.5 No. 25 1.0 solution No. 143 Electrolyte 0.5 No. 27 1.0 solution No.144 Electrolyte 0.5 No. 29 1.0 solution No. 145 Electrolyte 0.5 No. 321.0 solution No. 146 Electrolyte 0.5 No. 35 1.0 solution No. 147Electrolyte 0.5 No. 37 2Na⁺ 1.0 solution No. 148 Electrolyte 0.5 No. 411.0 solution No. 149 Electrolyte 0.5 No. 46 1.0 solution No. 150Electrolyte 0.5 No. 50 1.0 solution No. 151 Electrolyte None — None — —solution No. 152 Electrolyte No. 2  0.5 — solution No. 153 ElectrolyteNone — No. 15 Na⁺ 1.0 solution No. 154 Electrolyte No. 51 0.5 1.0solution No. 155 Electrolyte No. 2  0.5 No. 55 1.0 solution No. 156Electrolyte 0.5 No. 59 1.0 solution No. 157

TABLE 11 Discharge Positive Negative capacity Remaining AverageElectrolyte electrode electrode maintenance* capacity discharge solutionActive Active [%] After proportion* voltage* No. material material 200cycles [%] [%] Example 5-1 No.139 NaFe_(0.5)Co_(0.5)O₂ Hard 135 140 104Example 5-2 No.140 carbon 134 138 104 Example 5-3 No.141 123 119 103Example 5-4 No.142 131 138 103 Example 5-5 No.143 132 136 103 Example5-6 No.144 124 118 103 Example 5-7 No.145 123 120 103 Example 5-8 No.146122 120 103 Example 5-9 No.147 110 108 102 Example 5-10 No.148 133 139103 Example 5-11 No.149 122 117 103 Example 5-12 No.150 120 118 103Example 5-13 No.151 102 103 102 Comparative No.152 100 100 100 example5-1 Comparative No.153 99 98 98 example 5-2 Comparative No.154 102 94 99example 5-3 Comparative No.155 99 98 97 example 5-4 Comparative No.15693 90 99 example 5-5 Comparative No.157 95 92 98 example 5-6 *Relativevalue when the result of Comparative example 5-1 is designated as 100.

From the above results, even in a sodium ion battery, it was confirmedthat a high-temperature cycle characteristic, high-temperature storagecharacteristic and low-temperature output characteristic were improvedby using the first compound and the second compound in combination, ascompared with Comparative example 5-2 wherein the first compound wasused alone. Similarly, it was also confirmed that a high-temperaturecycle characteristic, high-temperature storage characteristic andlow-temperature output characteristic were improved as compared withComparative example 5-3 wherein the second compound was used alone. Asshown in the case of Comparative example 5-4 wherein R² of the firstcompound represented by general formula (1) is not a linear or branchedC₁₋₁₀ alkyl group (R² in Comparative example 5-4 contains a fluorinegroup), a low-temperature output characteristic was decreased and noimprovement was confirmed in a high-temperature cycle characteristic orhigh-temperature storage characteristic.

As shown in the case of Comparative example 5-5 wherein the secondcompound contained neither a P—F bond nor an S—F bond, no improvementwas confirmed in a high-temperature cycle characteristic,high-temperature storage characteristic or low-temperature outputcharacteristic.

As shown in the case of Comparative example 5-6 wherein the secondcompound contains a P—F bond but has a structure where the substituentis bonded to a P atom is not a hydrocarbon group containing anintervening oxygen atom (e.g., an alkoxy group) but a hydrocarbon groupcontaining no intervening oxygen atom (i.e., an alkyl group), alow-temperature output characteristic was decreased and no improvementwas confirmed in a high-temperature cycle characteristic orhigh-temperature storage characteristic.

The invention claimed is:
 1. An electrolyte solution for a non-aqueouselectrolyte battery, comprising at least a non-aqueous solvent, asolute, at least one silane compound selected from the group consistingof the following Compound Nos. 1 to 13 as a first compound, and at leastone compound selected from the group consisting of fluorine-containingcompounds represented by the following formulae (2) and (3) as a secondcompound:

wherein M¹ represents a proton, a metal cation or an onium cation,wherein the anion of said fluorine-containing compound represented bythe formula (2) is:

and wherein the anion of said fluorine-containing compound representedby the formula (3) is selected from the group consisting of thefollowing Compound Nos. 15 to 24:


2. The electrolyte solution for a non-aqueous electrolyte batteryaccording to claim 1, wherein the amount of said first compound rangesfrom 0.001 to 10.0% by mass relative to the total amount of theelectrolyte solution for a non-aqueous electrolyte battery.
 3. Theelectrolyte solution for a non-aqueous electrolyte battery according toclaim 1, wherein the amount of said second compound ranges from 0.001 to10.0% by mass relative to the total amount of the electrolyte solutionfor a non-aqueous electrolyte battery.
 4. The electrolyte solution for anon-aqueous electrolyte battery according to claim 1, wherein M¹ in saidformulae (2) and (3) represents a lithium ion, a sodium ion, a potassiumion, a tetraalkylammonium ion or a tetraalkylphosphonium ion.
 5. Theelectrolyte solution for a non-aqueous electrolyte battery according toclaim 1, wherein said solute is at least one solute selected from thegroup consisting of lithium hexafluorophosphate, lithiumtetrafluoroborate, lithium bis(trifluoromethanesulfonyl)imide, lithiumbis(fluorosulfonyl)imide, lithium bis(difluorophosphoryl)imide, sodiumhexafluorophosphate, sodium tetrafluoroborate, sodiumbis(trifluoromethanesulfonyl)imide, sodium bis(fluorosulfonyl)imide andsodium bis(difluorophosphoryl)imide.
 6. The electrolyte solution for anon-aqueous electrolyte battery according to claim 1, wherein saidnon-aqueous solvent is at least one non-aqueous solvent selected fromthe group consisting of a cyclic carbonate, a linear carbonate, a cyclicester, a linear ester, a cyclic ether, a linear ether, a sulfonecompound, a sulfoxide compound and an ionic liquid.
 7. A non-aqueouselectrolyte battery, comprising at least a positive electrode, anegative electrode, a separator, and the electrolyte solution for anon-aqueous electrolyte battery according to claim 1.